Navigation Links
Caffeine's effect on the brain's adenosine receptors visualized for the first time
Date:11/1/2012

Reston, Va. (November 1, 2012) Molecular imaging with positron emission tomography (PET) has enabled scientists for the first time to visualize binding sites of caffeine in the living human brain to explore possible positive and negative effects of caffeine consumption. According to research published in the November issue of The Journal of Nuclear Medicine, PET imaging with F-18-8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine (F-18-CPFPX) shows that repeated intake of caffeinated beverages throughout a day results in up to 50 percent occupancy of the brain's A1 adenosine receptors.

"The effects of caffeine to the human body are generally attributed to the cerebral adenosine receptors. In the human brain the A1 adenosine receptor is the most abundant," said David Elmenhorst, MD, lead author of "Caffeine Occupancy of Human Cerebral A1 Adenosine Receptors: In Vivo Quantification with F-18-CPFPX and PET." "In vitro studies have shown that commonly consumed quantities of caffeine have led to a high A1 adenosine occupancy. Our study aimed to measure the A1 adenosine receptor occupancy with in vivo imaging."

Fifteen male volunteers participated in the study. They abstained from caffeine intake for 36 hours and then underwent a PET scan with F-18-CPFPX. Caffeine was then introduced in short intravenous infusions, increasing in amount. To estimate the occupancy of A1 adenosine receptors by caffeine, the distribution volume at the baseline period of the PET scan was compared with the distribution volume after caffeine administration. Researchers determined that the concentration of the caffeine that displaces 50 percent of the binding of F-18-CPFPX to the A1 adenosine receptor was 13 mg/L, or approximately four to five cups of coffee.

An important finding of the study is that in most regular coffee drinkers about half of the A1 adenosine receptors may be occupied by caffeine. It is likely that this blockage of a substantial amount of cerebral A1 adenosine receptors will result in adaptive changes and lead to chronic alterations of receptor express and availability.

"There is substantial evidence that caffeine is protective against neurodegenerative diseases like Parkinson's or Alzheimer's disease," noted Elmenhorst. "Several investigations show that moderate coffee consumption of 3 to 5 cups per day at mid-life is linked to a reduced risk of dementia in late life. The present study provides evidence that typical caffeine doses result in a high A1 adenosine receptor occupancy and supports the view that the A1 adenosine receptor deserves broader attention in the context of neurodegenerative disorders."

Caffeine is the most commonly consumed psychoactive substance worldwide and an active ingredient in innumerable food and beverages. Eighty percent of U.S. adults consume caffeine every day; the average for adults is 200 mg of caffeine per day (two 5-ounce cups of coffee or four sodas). It affects an individual's alertness, attention, cognitive performance, as well as reduces sleepiness.


'/>"/>

Contact: Susan Martonik
smartonik@snmmi.org
703-652-6773
Society of Nuclear Medicine
Source:Eurekalert

Related medicine news :

1. New MS drug proves effective where others have failed
2. New study shows effects of prehistoric nocturnal life on mammalian vision
3. Health inequalities could be reduced by more effective health care, says new study
4. Health inequalities could be reduced by more effective healthcare, says new study
5. Genes May Determine Aspirins Effect on Advanced Colon Cancer
6. As painkiller overdoses mount, researchers outline effective approaches to curb epidemic
7. Is magnetic therapy effective for tinnitus?
8. Considerably more patients may benefit from effective antidiabetic drug
9. Surgery more profound effect than anesthesia on brain pathology, cognition in Alzheimers mice
10. NIH-funded analysis estimates effective PrEP dosing
11. Effects of stopping alcohol consumption on subsequent risk of esophageal cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/13/2017)... ... October 13, 2017 , ... Dickinson Insurance and Financial ... financial preparation services, is providing an update on a charitable event that began ... Rescue is a locally recognized nonprofit that provides shelter and care for animals ...
(Date:10/13/2017)... ... October 13, 2017 , ... The American Board of Family Medicine's (ABFM) Board ... Chief Executive Officer, succeeding Dr. James C. Puffer upon his retirement. Dr. Newton will ... Dr. Puffer’s retirement at the end of 2018. Upon assuming the role of President ...
(Date:10/13/2017)... ... October 13, 2017 , ... ... Hannah Randall, PharmD ‘17, and Jennifer Huggins, PharmD ’17, along with clinical ... the primary prevention of cardiovascular diseases during the 15th Annual Women’s Health ...
(Date:10/13/2017)... SAN LUIS OBISPO, Calif. (PRWEB) , ... October 13, 2017 , ... ... with Alzheimer’s or dementia. However, many long-term care insurance companies have a waiver for ... mean is the 90-day elimination period, when the family pays for care, is often ...
(Date:10/13/2017)... ... 2017 , ... Global Healthcare Management’s 4th Annual Kids Fun Run brought out ... free event, sponsored by Global Healthcare Management’s CEO, Jon Letko, is aimed at getting ... children of all ages; it is a non-competitive, non-timed event, which is all about ...
Breaking Medicine News(10 mins):
(Date:10/2/2017)... 2, 2017  Eli Lilly and Company (NYSE: ... the third quarter of 2017 on Tuesday, October 24, ... that day with the investment community and media to ... conference call will begin at 9 a.m. Eastern time. ... live webcast of the conference call through a link ...
(Date:9/28/2017)... , Sept. 28, 2017 Hill-Rom Holdings, ... 2017 earnings conference call and webcast on Friday, November ... a.m. (EDT) and ending at approximately 8:30 a.m. (CDT) ... discussing the company,s 2017 financial performance and guidance for ... opportunities, initiatives to enhance operational performance, and long-range financial ...
(Date:9/25/2017)... --  Montrium , an industry leader in powerful ... Trial Master Files & Inspection Readiness Conference ( ... Services has selected eTMF Connect to ... a leading European contract research organization (CRO), will ... enable greater collaboration with sponsors, improve compliance and ...
Breaking Medicine Technology: